The present invention relates to a liquid crystal projector having a video monitor, and particularly to a liquid crystal projector having a video monitor in which an image projected from the liquid crystal projector and displayed on a screen located in front of the liquid crystal projector can be viewed through another screen installed in the liquid crystal projector.
In the liquid crystal projector, dichroic mirrors separate white light projected from a light source into blue, green and red light, and a liquid crystal panel applies an electrical video signal to the color light obtained through the color separation. The color light to which the video signal is applied is projected by a projection lens so as to be displayed on a screen as an image of which the focus is adjusted. The dichroic mirrors require the characteristics in which the respective color light which is reflected or transmitted among the blue, green and red light can be completely reflected or transmitted, in order to provide a light image of a high quality. However, the dichroic mirrors used for the color separation in the liquid crystal projector do not generally full-reflect or completely transmit incident light. Thus, such dichroic mirrors reflect about ten percent of the color light in a transmission band, and also transmit about ten percent of the color light in the reflection band according to the transmission and reflection characteristic.